Microelectronic devices, such as thin film transistors (TFTs), may include oxide semiconductor channel layers. Use of oxide semiconductor channel layers may allow the fabrication of optically transparent TFTs, and may allow process advantages such as low temperature processing on plastic substrates. However, oxide semiconductor channel layers may exhibit fabrication challenges such as increased channel conductivity following certain process steps, such as photolithographic patterning. Increased conductivity of the oxide semiconductor channel layer may result in a TFT that is not easily turned off. Accordingly, there may be a need to provide a process to produce TFTs including oxide semiconductor channel layers having reduced conductivity.